A self-propelled agricultural machine such as a thresher, combine, or field chopper must have a rigid chassis supporting the engine, the fuel tank, the intake device, the treatment (e.g. threshing, chopping) equipment, the operator cabin, and normally some sort of conveyor or baler for the crop. In addition the operator cabin must be held in a location giving the operator a good vantage point of whatever is being done.
Typically a flat generally rectangular frame is used to support everything. This is the system shown in East German Pat. No. 75,665 issued Apr. 20, 1972 to K. Oliva et al which has three parallel longitudinal beams on which all the equipment is secured. Another such structure is seen in East German Pat. No. 104,902 issued Apr. 5, 1974 to V. Miratsky et al, one that is intended for use by different types of machinery. These systems are disadvantageous because it is frequently difficult to gain access to some parts of the machinery without removing others, that stand in the way or surround them.
In particular such a general-use chassis can rarely support a large front-end intake unit well. East German Pat. No. 112,705 of K. Oliva describes an arrangement for doing this which is complex in the extreme, making servicing quite difficult. Similarly the arrangement of German Pat. No. 2,412,461 of F. Schollhorn et al requires a very complicated chassis for carrying a front-end intake unit.
Another disadvantage of the known machines is that the operator cabin normally sits on top of the whole chassis. In this position it is subject to all of the vertical jarring and transverse swaying and shaking to which such a heavy-duty machine is prone. Such arrangements can be seen in German patent documents Nos. 2,935,274, 3,011,232, and 3,011,089 respectively of A. Grunecker et al, F. Philips et al, and E. Priepke et al, the latter two citing as priority U.S. application Ser. Nos. 26,499 and 26,500 of 1979. Operator efficiency falls off considerably when the operator cabin is subjected to such movements.